One of the problems with async is that it's viral. Make a function async and your entire call graph has to be made async, unless they handle the future manually

One of the problems with async is that it's viral. Make a function async and your entire call graph has to be made async, unless they handle the future manually without await. Async introduces a new "colour" to the language. Not in Rust. Or C#. Or any language except JavaScript. In Rust, a synchronous function can call and block on an async function with executor::block_on(). C# has Task.Wait() and Task.Result(). Python 3 has asyncio.run(). Scala has Await.ready() and Await.result(). Kotlin has runBlocking {}.